Influence of mass of ruminal contents on voluntary intake and digesta passage in steers fed a forage and a concentrate diet1

Abstract

To evaluate the influence of mass of ruminal contents on voluntary intake and ruminal function, five ruminally cannulated steers (550 kg) were fed an orchard grass hay diet ad libitum in a 5 x 5 Latin square experiment. The mass of ruminal contents was altered by adding varying weights of modified tennis balls to the rumen before the initiation of each 15-d experimental period. Treatments consisted of 50 balls with a specific gravity of 1.0, 1.1, 1.2, 1.3, or 1.4; the total weight of the balls was 7.45, 8.50, 9.25, 10.55, and 11.55 kg, respectively. Increasing the specific gravity of the balls added to the rumen decreased DMI and particle passage rate (P < 0.05) in a linear manner. A second experiment was conducted to evaluate the influence of mass of ruminal contents on voluntary intake and ruminal function of both forage and concentrate diets. Five ruminally cannulated steers (580 kg) were fed a 70% concentrate (DM basis) or an orchardgrass hay diet ad libitum in a 5 x 5 Latin square experiment. The mass of ruminal contents was altered as in the first experiment. Treatments consisted of 0 balls added to the rumen of steers fed concentrate diet (control), 75 balls with a specific gravity of 1.1 given to steers fed a concentrate diet, 75 balls with a specific gravity of 1.4 given to steers fed a concentrate diet, 75 balls with a specific gravity of 1.1 given to steers fed a hay diet, and 75 balls with a specific gravity of 1.4 given to steers fed hay diet. The addition of balls to the rumen of steers fed the concentrate diet decreased DMI (P < 0.05) compared with the 0-ball treatment, and increasing specific gravity of balls also decreased DMI (P < 0.01) for both concentrate and hay diets. Adding balls to the rumen of steers fed the concentrate diet decreased particle passage rate (P < 0.05), whereas increasing specific gravity of balls decreased particle passage rate for both concentrate and hay diet. The results of this study suggest that the density of ruminal digesta can have an influence on voluntary intake of both forage and concentrate diets.

Nutrient digestibility, fecal output and eating behavior for different cattle background feeding strategies

“…The targeted crude protein intake for both rations was designed to be similar; however, the ad libitum-fed high-forage steers consumed somewhat less DM in the digestibility trial than expected (2.3% vs. an expected intake of 2.5% of body weight on a DM basis). Thus, crude protein digestion by the ad libitum-fed high-forage steers might have been greater than expected due to a slower passage rate and increased rumen retention time (Whetsell et al 2004).…”

Assessing the Jarman–Bell Principle: Scaling of intake, digestibility, retention time and gut fill with body mass in mammalian herbivores

“…a) OMI and MRT; b) OMI and 903 OMC; c) MRT and aDOM; d) MRT and OMC. For statistics, see (Luginbuhl et al, 1990) Pudu puda 4 1 9.1 0.299 29.9 75.2 0.232 (Conklin-Brittain and Dierenfeld, 1996) Cephalophus maxwellii 4 1 9.4 0.305 42.2 73.0 0.341 (Conklin-Brittain and Dierenfeld, 1996) Capreolus capreolus 4 >1 24.7 0.405 27.0 67.7 0.302 (Holand, 1994) Capra hircus 4 1 29.7 0.777 45.9 51.3 1.117 Freudenberger and Hume, 1992;Kennedy et al, 1992) (Foot and Romberg, 1965;McIntosh, 1966;Forbes and Tribe, 1970;Dellow, 1982;Dellow and Hume, 1982;Luginbuhl et al, 1990;Kennedy et al, 1992;Pearson et al, 2006 Jiang and Hudson, 1996) (Schaefer et al, 1978;Colucci et al, 1982;Mathers et al, 1989;Luginbuhl et al, 1994;Burns et al, 1997;Whetsell et al, 2004;Pearson et al, 2006) (Cahill and McBride, 1995) GIT-Anatomy = gastrointestinal tract anatomy: 1 = caecum fermenter, 2 = colon fermenter, 3 = nonruminant foregut fermenter, 4 = ruminant foregut fermenter; BM = body mass; DMI = dry matter intake; MRT = mean retention time of particle markers (different markers) through the whole gastrointestinal tract; aD DM = apparent dry matter digestibility; DMC= mass of dry matter gastrointestinal tract content calculated according to Holleman and White (1989; for equations see the main text) Table 3.…”

Carcass yield, cuts and body components in lambs fed a pineapple by-product silage diet

“…The linear increase in the HCY and CCY was likely caused by lower neutral detergent fibre corrected for ash and protein (NDFap) content after the addition of pineapple by-product silage to the diets (Table 1) because the HCW and CCW did not differ among the treatments (P>0.05; Table 2), and the GIT content decreased with the addition of pineapple byproduct silage to the diets, as explained later (P<0.05, Table 4). The different organizational arrangements in the NDF fraction result in different degrees of substrate availability to rumen microorganisms, which may alter the digestion rate and, consequently, the rate of food passage through the rumen (Whetsell et al, 2004). Therefore, NDF constituents contribute significantly to the permanence of food along the GIT, which may affect carcass yield.…”